The invention relates to the processing of strips of material, particularly strips of photographic prints arranged in successive groups, each group constituting a customer order. Conventionally, such strips are provided with end-of-order markings near the end of each order coordinated with the last print in the order, and with individual-print markings coordinated with the individual prints. These markings are used to properly synchronize severing and sorting operations.
In automatic photographic printers, during the printing operation, the back side of the strip of printing paper is provided with end-of-order markings and individual-print markings such as just referred to. The individual-print markings are detected at a severing station, and in coordination with such detection the individual prints are severed one from the next. The end-of-order markings are detected and are used to control the sorting of the different customer orders. Alternatively, the end-of-order markings may be used to sever the last print of one order from the first print of the next, when the prints are not individually severed. The sorting operation may involve transport of the different orders at spaced time intervals to a station where the prints and the negatives are inserted into envelopes, or other such transport operations.
Usually, the aforementioned markings are not located in exact coincidence with the portion of the strip upon which the operations synchronized by the markings are actually performed. For example, the individual-print markings are usually not located coincident with the cut lines to be formed at the severing station, but instead are located upstream of the respective cut lines, so that these markings will be detected at a location upstream of the actual severing station. The same generally applies to the end-of-order markings which are detected by a detector located upstream of the actual sorter for the different orders.
A problem with known processing techniques involving these markings is that their locations relative to ends of orders and the individual prints necessitate forward transport of the strip through the severing and sorting stations, in correspondence to the forward transport of the strip through the exposure and developing stations of the printer. However, it is usually the case that, during the forward transport of the strip through the printer, the strip is forward-transported through a monitoring station located downstream of the printer, for automatic and/or subjective checking of the quality of the prints. The forward-transported strip is then fed to a take-up roller, or the like, and rolled up. Consequently, the accessible end of the rolled-up strip is the trailing end thereof, making it impossible to directly feed the strip off the take-up roll for forward transport through the severing and sorting stations. Instead, it is necessary to unroll the strip from the take-up roller, and then reroll it, for example, on a different take-up roller, so that the accessible end of the rerolled strip will be its leading end. The leading end can then be pulled off the take-up roller and fed to the severing and sorting stations for forward transport of the strip therethrough. This constitutes an inconvenient intermediate operation.